Adhesive wafers for ostomy appliances or wound dressings are usually in the form of a backing layer coated on the skin-facing surface with an adhesive layer. Even if both the adhesive and the backing layer are soft and flexible, the skin surface onto which the wafer is applied will move dependent on the wafers movements, a movement at the edge of the wafer may cause a stress transmitting through the entire wafer. This may cause discomfort and trauma to the skin and build up tension in the wafer, leading to loosening of its tack and increasing the risk of leakage. In an ostomy appliance the wafer typically carries a collecting bag, said bag may also induce pulling and dragging forces to the wafer. Such forces induced in the wafer are often lateral, i.e. parallel to the wafer, and the known wafers are not very flexible with respect to lateral movements.
From European patent No. 768 071 is known a wound dressing comprising a hydrocolloid containing adhesive layer, a flexible backing film secured to the non-skin contacting side of the adhesive layer, said backing film having at least one linear depression, the thickness of the adhesive in the depression being less than the thickness of the adhesive layer alongside the depression. The adhesive layer is continuously covering the backing film, and provides a continuous adhesive surface against the skin, but the layer of adhesive is thinner in the depressions than in the surrounding parts. These depressions make the dressing more flexible and easier to bend when applied to curved surfaces, e.g. sacrum.
European patent No. 591 440 discloses a wound dressing, preferably of the hydrocolloid type, in which is made grooves or ditches that fully or partly surrounds a central part of the adhesive sheet. The grooves and ditches are arranged concentric or radially outwardly from the central part and have a depth so that the thickness of the sheet at the bottom of the ditch is less than ¼ of the thickness of the sheet between the ditches. The ditches and grooves facilitate a higher flexibility of the dressing with respect to bending as well as they can work as a stop point to the absorbed fluid.
The ostomy appliances disclosed in both European patent No. 591 440and European patent No. 768 071 both suffer from the drawback that even though the depressions/grooves in the dressings add greater flexibility to the dressing, this flexibility is only in the bending and curving process. European patent No. 591 440 and European patent No. 768 071 do not teach or indicate lateral flexibility to allow sideward stretching of an ostomy appliance, or individual movement of select parts of the dressing. Such separate movements are not possible for the embodiments shown in European patent No. 591 440 and European patent No. 768 071.
From European patent No. 898 471 is known a wound dressing comprising a backing layer, an absorbent layer and a skin-contacting layer. The dressing is provided with one or more seals circumscribing the central portion. The seals are made by applying ultrasonic or thermal energy thus creating a groove from the skin surface to the backing layer, the sides of said groove being covered with a water-impervious material, e.g. adhesive. The seals serve as barriers for leakage. The reference is silent with respect to the ability of lateral movement.
It has surprisingly been found that it is possible to provide an adhesive wafer having lateral flexibility offering a convenient and comfortable solution to the above problems.